Method of removing oil from a mixture of tool steel swarf granular material and oil

ABSTRACT

A method of removing oil from a mixture of tool steel swarf granular material and oil. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

BACKGROUND

1. Technical Field

This application relates to a method of removing oil from a mixture oftool steel swarf granular material and oil.

2. Background Information

This application relates to the process conditions in utilizingsupercritical carbon dioxide (SCCO₂) for substantial removal of residualcutting fluids, either oils and/or water, and at least partial removalof other contaminants from industrial grindings of tool steels that maybe contaminated with aqueous and/or oil-based residual contaminates. Thecontaminant liquid can be recycled for reuse, and the solids can berecycled or remelted in the smelting process for reuse. If thecontaminants are not removed, they present an environmental hazard whenthey are land filled or incinerated.

Supercritical carbon dioxide is carbon dioxide that is at a temperatureand a pressure greater than Tr=1 and Pr=1. (Tr is T/Tc where T is thepresent temperature of the supercritical carbon dioxide and Tc is thecritical temperature. Pr is P/Pc where P is the present pressure of thesupercritical carbon dioxide and Pc is the critical pressure.) Tc, thecritical temperature for carbon dioxide (CO₂), is 31.1 degrees Celsius(° C.), or 304.1 degrees Kelvin (K), and Pc is 73 atmospheres (atm) orabout 1073 pounds per square inch (PSI).

In more general terms, supercritical carbon dioxide refers to carbondioxide that is in a fluid state while also being at or above both itscritical temperature and pressure. Carbon dioxide usually behaves as agas in air at standard temperature and pressure (STP) or as a solidcalled dry ice when frozen. If the temperature and pressure are bothincreased from standard temperature and pressure to be at or above thecritical point for carbon dioxide, it can adopt properties midwaybetween a gas and a liquid. More specifically, it behaves as asupercritical fluid above its critical temperature (31.1° C.) andcritical pressure (73 atm), expanding to fill its container like a gasbut with a density like that of a liquid. The supercritical fluid regionof the phase diagram is defined as a temperature above the criticaltemperature (31.1° C.) to a pressure above the critical pressure (73.8bar or 1070 PSI).

SUMMARY

At least one possible embodiment of the present application teaches amethod for the removal of oil from a mixture of granular material andoil using supercritical carbon dioxide. It was found, throughexperimentation, that the supercritical carbon dioxide extraction ofhigh speed steel (HSS) grinding swarf can, in at least one possibleembodiment of the present application, produce a solids high speed steelproduct with less than 5% (by weight) cutting oil. In at least onepossible embodiment, there can be as low as 0.44% (by weight) oil in theextracted solids.

A typical high speed steel swarf analysis is presented in Table A asfollows:

TABLE A Analysis Weight Percent Molybdenum (Mo) 3.75 Tungsten (W) 1.90Vanadium (V) 0.98 Chromium (Cr) 2.75 Cobalt (Co) 0.57 Phosphorus (P)0.040 Silica (SiO₂) 5.75 Alumina (Al₂O₃) 3.00 Oil 22.5 Iron (Fe)(Balance)

The source of the aluminum oxide (alumina) is the grinding media. Theprincipal source of the silicon dioxide (silica) is diatomaceous earth.This is often added for ease of filtration in trying to remove as muchoil as possible from the swarf prior to land-filling.

The following represents the physical and chemical characteristics ofHigh speed steel grinding swarf:

Solids:

-   -   High speed steel—same composition as presented in Table A    -   Particle sizes of swarf in Table A—median 400 mesh, or 37        micrometers (μ); particle size diameter (PSD), such as a mean        diameter of the particles, from 10 micrometers to 300        micrometers; particles generally irregularly shaped and        generally not spherical.

Contaminant:

-   -   A complex mixture of hydrocarbons    -   Mixture, mostly paraffinic, but also some high MW oxy compounds    -   Component analysis as follows:        -   C₆ to C₁₀=˜0.05% (by weight)        -   C₁₀ to C₁₆=˜1.06% (by weight)        -   C₁₆ to C₂₉=˜4.0% (by weight)        -   C₂₉ and higher=˜94.9% (by weight)            Expressed Differently the Component Analysis is as Follows:    -   H₁₄C₆ to H₂₂C₁₀=˜0.05% (by weight)    -   H₂₂C₁₀ to H₃₄C₁₆=˜1.06% (by weight)    -   H₃₄C₁₆ to H₆₀C₂₉=˜4.0% (by weight)    -   H₆₀C₂₉ and higher=˜94.9% (by weight).

In at least one possible embodiment of the present application, theparticle sizes are primarily in the range of 10 to 100 micrometers. If ascreen analysis of dried swarf is completed, at least 50% of thematerial by weight will pass through a standard 325 mesh screen. Thescreen opening for the 325 mesh screen is 45 micrometers. At least 98%of this material by weight will pass through a 80 mesh screen which hasa screen opening of about 177 micrometers.

In a screen analysis of a high speed steel swarf sample, oil was removedfrom a mixture of granular material and oil using supercritical carbondioxide (CO₂). The following Table B presents these results:

TABLE B U.S. mesh Micrometers Percent by +80 212 0.7 +100 150 0.7 +17090 6.9 +200 75 5.2 +230 63 5.2 +270 53 7.2 +325 45 12.4 +400 37 26.2+500 25 31.5 −500 <25 2.1In this case, the median size (based on numbers of particles) was 39micrometers.

Concerning non-metallic swarf components, diatomaceous earth is oftenused in such equipment as Coopermatic Filters to filter swarf from thegrinding oil in manufacturing plants of the tool maker. Another productwhich is used in certain tool steel drill making plants that generateswarf is the Eagle Pitcher CELETOM FW 60.

This application relates to the process configuration usingsupercritical carbon dioxide in order to successfully remove as much asgreater than 98% (by weight) of such contaminants from the feed solids,since the reuse of such “clean solids” is predicated on a contaminantlevel at approximately 0.5% to 2% (by weight). Using carbon dioxide asthe working fluid or extraction solvent, at least one embodiment of thepresent application utilizes carbon dioxide cycling in and out of thesupercritical state to convert a metal waste by product into a reusableliquid contaminant and substantially liquid contaminant-free solids,both of which can be reused with relatively small waste. The carbondioxide may also be re-circulated and reused.

It is not necessarily desirable to produce a solids product with 0%contaminant (oil) since pure metals and/or alloys with high surfaceareas per weight, such as high speed steel, can undergo rapid oxidationwith air, especially for very high surface area fines. Not only can thetemperature increases be large, there can or may be auto-ignition, suchas an explosion, of certain metals or alloys. Therefore, from a processpoint-of-view, removal of as much contaminant as possible should bepromoted or maximized, while still leaving a minimum amount sufficientto suppress spontaneous reaction during contact with air (oxygen) duringthe handling and transport of the purified solids.

In this regard, it is sufficient to leave approximately 0.5% to 2% (byweight) contaminant oil on high speed steel product. For other examplesof metals and alloys, it may be sufficient to leave a differentcontaminant level, predicated by the oxidation chemistry for eachspecific solid material in the cleansed product.

For extracted high speed steel swarf solids product, therefore, it maybe sufficient to leave 0.5 to 2% (by weight) residual contaminant forhandling and storage purposes, while re-melting such solids product canbe easily and safely carried out.

The above-discussed embodiments of the present invention will bedescribed further hereinbelow. When the word “invention” or “embodimentof the invention” is used in this specification, the word “invention” or“embodiment of the invention” includes “inventions” or “embodiments ofthe invention”, that is the plural of “invention” or “embodiment of theinvention”. By stating “invention” or “embodiment of the invention”, theApplicant does not in any way admit that the present application doesnot include more than one patentably and non-obviously distinctinvention, and maintains that this application may include more than onepatentably and non-obviously distinct invention. The Applicant herebyasserts that the disclosure of this application may include more thanone invention, and, in the event that there is more than one invention,that these inventions may be patentable and non-obvious one with respectto the other.

BRIEF DESCRIPTION OF THE DRAWINGS

At least one possible embodiment of the present application will bedescribed by means of the accompanying drawings, in which:

FIG. 1 is a graph showing results from supercritical carbon dioxideextraction of high speed steel grinding swarf;

FIG. 2 is a diagram showing the process for carrying out thesupercritical carbon dioxide extraction of high speed steel grindingswarf;

FIG. 3 is a graph showing further results from supercritical carbondioxide extraction of high speed steel grinding swarf;

FIG. 4 is a graph showing the percentage of oil extracted during aprocess of supercritical carbon dioxide extraction of high speed steelgrinding swarf; and

FIG. 5 is a graph showing the percentage of oil remaining after aprocess of supercritical carbon dioxide extraction of high speed steelgrinding swarf has been completed.

DESCRIPTION OF EMBODIMENT OR EMBODIMENTS

The swarf, as analyzed in Tables A and B, was sent to SupercriticalSolutions LLC, 2845 Rolling Green Place, Macungie, Pa., 28062, to removeoil from the mixture of granular material and oil, and Table 1 shows theresulting data. In at least one possible embodiment of the presentapplication, a small sample of high speed steel swarf was loaded into aprocess development unit (PDU), brought to temperature, either by directand/or indirect heat transfer, to 24° C., and pressurized to 1700 PSI.The sample was extracted by passing pure subcritical carbon dioxidethrough the bed, continuously, over a two-hour (120 min) period. Thesample of initial high speed steel swarf feed contained approximately12.4%, (by weight) contaminant oil. It should be noted that othersamples of swarf could contain levels of contaminant oil other than12.4%.

Samples of treated swarf were taken and analyzed intermittently over theduration of the experiment. The effluent carbon dioxide from the bed wasdepressurized, dropping-out the extracted oil in another, separatevessel. The samples were analyzed every ten minutes, and after 120minutes, the bed was depressurized, the contents emptied, and analyzed.The following Table 1 presents these results:

TABLE I PDU EXPERIMENTS SCCO₂ EXTRACTION OF HIGH SPEED STEEL GRINDINGSWARF Residue Extracted Oil in Cumulative Press. Temp. Weight Oil % Oilin % Oil in Residue Residence % Oil Run No. (PSI) ° C. (grams) (grams)Feed Residue (grams) Time (min) Removed 1 1700 24 26.15 3.69 12.4 10.62.77 120 57.1 2 4300 55 46.01 11.53 20.0 2.92 1.34 120 89.6 3 4350 5023.38 6.03 20.5 2.36 0.55 120 91.6 4 5000 60 48.52 12.73 20.8 3.26 1.58100 88.9 5 5000 64/65 22.39 6.39 21.9 1.52 0.34 80 94.9 6 8700 80 23.856.52 21.5 0.44 0.10 50 98.4 7 9000 90 25.70 6.20 19.4 1.02 0.26 80 95.98 9000 100 24.92 5.72 18.7 1.74 0.43 80 92.9 9 9200 100 25.54 5.66 18.11.84 0.47 85 92.3 10 9200 110 24.99 4.80 16.1 1.04 0.26 55 94.9 11 9200110 25.12 5.98 19.2 0.93 0.23 65 96.2

In Run 1, the starting feed contained 12.4% oil, and the extractedsample of high speed steel product contained 10.6% (by weight) oil aftera total processing residence time of 120 minutes. The oil removed fromthe feed was approximately 57.1% (by weight).

Another sample of high speed steel swarf was subjected to the processdevelopment unit and processed at supercritical carbon dioxideconditions, at 4300 PSI, and at 55 C.°, as noted in Run 2 in Table 1.The oil extracted was approximately 89.6% (by weight) at a residencetime of 120 minutes.

In Run 3, the pressure was 4350 PSI, the temperature was 50° C., and theamount of feed in the PDU was approximately one half the amount in Run2. From Table 1, it can be noted that the oil removal increased from89.6% to 91.6% just by lowering the operating temperature 5° C., from 55to 50° C. Again, the residence time was 120 minutes.

In Run 4, the pressure was 5000 PSI and temperature was 60° C., and theoil removal was approximately 88.9% (by weight) after a residence timeof 100 minutes.

In Run 5, the temperature was 64/65° C. and a pressure of 5000 PSI wasemployed. Run 5 produced an oil removal of approximately 95% (byweight). The residence time was approximately 80 minutes.

Run 6 was carried out at a pressure of 8700 PSI and a temperature of 80°C. With a residence time of approximately 50 minutes, a 98.4% (byweight) removal of the contaminant oil was achieved.

The pressure was 9000 PSI at a temperature of 90° C. in Run 7. A sharpreduction in oil removal was found, down to 95.9% oil removal, and evenwith additional variations of pressure up to 9200 PSI and temperature upto 110° C. (Runs 8, 9, and 10), the oil removal rates appeared to take adownturn.

Runs 7 through 11 were carried out at residence times of 55-85 minutes.

For the Runs presented in Table 1, not only were the conditions oftemperature and pressure closely maintained, bed size and solvent tofeed ratio (gms CO₂/gms sample), also known as S/F, were closelycontrolled to obtain as high a contaminant removal as possible. Inaddition, residence time was carefully studied by taking samples duringthe Runs and analyzing the oil contents. These data are best summarizedin FIG. 1.

Using a continuous process development unit (PDU), carbon dioxide at theconditions noted was passed through a bed (size noted) of high speedsteel swarf and the contaminant oil removal (as % feed) was plottedagainst the cumulative amount of carbon dioxide being passed through thesample over the total residence time, as shown on FIG. 1. Althoughend-point data are tabulated in Table 1, at least 5 to 10 data pointscollected during the Runs were used to construct Curves A through K, asshown in FIG. 1. For clarity purposes, some are depicted in FIG. 1 toelucidate the differences. The region between 8700 PSI and 9200 PSIrepresents the contaminant removal, as noted in FIG. 1 for Curves G, H,and J. Note that the curve letters in FIG. 1 correspond to data pointsin the legend.

From the data in Table 1 and depicted in FIG. 1, it is concluded that anoptimum oil removal is achieved between 8700 PSI and 9000 PSI, or indeedat 8700 PSI. At 9000 and 9200 PSI, the oil removal decreased from amaximum of 98.4% to approximately 92% to 96%.

The process for carrying out the subject supercritical carbon dioxidesubstantial extraction of swarf can be generally depicted in FIGS. 2 and3. FIG. 2 is a diagram depicting a process using either pure and/orrecycled carbon dioxide. The pumps and heat exchangers are designed tomeet target Tr and Pr conditions at the prescribed solvent carbondioxide to feed high speed steel ratios. The size of the “feed andproduct beds” are dependent on the physical characteristics of the feedand the production rate desired. The number of beds can also vary (from2 as shown in FIG. 2) depending on production rate desired.

The process depicted in FIG. 2, two parallel stages, can be designed toyield 98+% oil contaminant removal from high speed steel, and othersimilar metallic waste products and other similar oil contaminants atextraction and desorption pressures of between 5000 PSI and 8700 PSI,and beyond, and at temperatures between 600 and 110° C. At 5000 PSI and65° C., a 94.9% oil removal was achieved, and at 8700 PSI and 80° C., a98.4% oil removal was achieved (see Table 1). Therefore, it is possible98+% oil removal could be achieved somewhere between 5000 PSI and 8700PSI, and/or beyond. It should be understood that other process optionsbesides two parallel stages may possibly be used in at least onepossible embodiment.

FIG. 3, used in conjunction with FIG. 2, is intended to “simulate” the“cycle” for contaminant removal from high speed steel swarf. Thesolubility data (mole fraction oil in carbon dioxide) is estimated fromthe reference by J. Yau et al., J. Chem. Eng. Data, 38, 174 (1993)extrapolated to higher pressures and temperatures. The oil is assumed tobe n-hexatriacontane (C₃₆) and its solubility in supercritical carbondioxide used in FIG. 3 to qualitatively depict the “cycle” used in FIG.2. Since the contaminant oil in high speed steel swarf is so complex, aswill be described later, herein, most of it is C₂₉+. Therefore,solubility data in supercritical carbon dioxide for the highest MWnormal paraffin found in the literature was used for FIG. 3.

Therefore, FIG. 3 is a solubility diagram with Points A through Fdepicted from FIG. 2. The only points truly at, or close to, equilibriumare Points A and B and A′, A″, B′, and B″. Points C, D, E and F are farfrom equilibrium, but at pressures and temperatures depicted on FIG. 3.Hence, the Points in any one cycle are represented by the Temperaturesand Pressures, and additionally, for Points A, A′, and A″, and B, B′,and B″, the solubility of oil in the supercritical carbon dioxide. (Allpoints A fall on the isobar desired, such as 4300 psi up to 9000 psi.)

FIG. 4 is a graph in which represents the percentage of oil extractedduring Runs 1-11 using the indicated pounds per square inch PSIpressure, as shown in Table 1. For instance, in Run 1, 57.1% of the oilwas removed using 1700 PSI. Run 2 resulted in 89.6% of the oil beingremoved using 4300 PSI. 91.6% of the oil was removed using 4350 PSI inRun 3. During Run 4, 88.9% of the oil was removed using 5000 PSI. Run 5resulted in 94.9% of the oil being removed using 5000 PSI. 98.4% of theoil was removed using 8700 PSI in Run 6. In Run 7, 95.9% of the oil wasremoved using 9000 PSI. Run 8 resulted in 92.9% of the oil being removedusing 9000 PSI. 92.3% of the oil was removed using 9200 PSI in Run 9.Run 10 resulted in 94.9% of the oil being removed in which 9200 PSI wasused. Run 11 resulted in 96.2% of oil being removed using 9200 PSI.

FIG. 5 is a graph, using information provided in Table 1, to show thepercentage of oil remaining after a process of supercritical carbondioxide extraction of high speed steel grinding swarf has beencompleted. For instance, in Run 1, 10.6% of the oil remained after using1700 PSI. Run 2 resulted in 2.92% of the oil remaining after using 4300PSI. 91.6% of the oil remained after using 4350 PSI in Run 3. During Run4, 3.26% of the oil remained after using 5000 PSI. Run 5 resulted in1.52% of the oil remaining after using 5000 PSI. 0.44% of the oilremained after using 8700 PSI in Run 6. In Run 7, 1.02% of the oilremained after using 9000 PSI. Run 8 resulted in 1.74% of the oilremaining after using 9000 PSI. 1.84% of the oil remained after using9200 PSI in Run 9. Run 10 resulted in 1.04% of the oil remaining after9200 PSI was used. Run 11 resulted in 0.93% of oil remaining after using9200 PSI.

Since high speed steel swarf is extremely dense (specific gravity (s.g.)of approximately 1.6), the sheer weight of the loaded process vessels atapproximately 100 pounds per cubic feet can be substantial. In addition,loading, processing, and emptying such large vessels in residence timesfrom 30 to 120 minutes can be a challenge for a large-tonnage plant. Onepossible option is to use a fewer number of large vessels with largeweights filled and emptied in a longer period of cycle time, or anotherpossible option is to use a larger number of smaller vessels withsmaller weights filled and emptied in a shorter period of cycle time. Inat least one possible embodiment, the size and cycle time for handlingsuch feed and product materials is selected to promote the supercriticalcarbon dioxide deep removal of this bulk contaminant oil.

It was determined that smaller vessels, in at least one possibleembodiment, with high length-to-diameter (L/D) ratios (cylindrical)would be suitable. First, high L/D ratios can be achieved, more easily,for small vessels that result in providing turbulence and good masstransport during extraction and desorption in this cyclic process. Underthese conditions of both high extraction and desorption rates, thepotential is high to realize high oil removal rates of 90+%, up to 98+%.Second, for smaller vessels, the volume of the vessels (V=_(π)D²L/4) canbe chosen as a function of vessel length and diameter. Once generalvessel volume and shape are chosen, a minimum residence time in thevessels should be maintained at the treat rates sufficient to obtainhigh bulk removal efficiencies.

In this type of high-pressure gas processing, it is possible to choose a“batch-type” system or choose a “continuous-type” system. The batchsystems can be used in parallel or in series, operated on a cyclic basis(at prescribed residence times), be sequentially loaded, processed, andunloaded, and yield a sufficient bulk removal efficiency. The“continuous-type” systems generally refer to a number of batch vessels,operated sequentially, with the supercritical carbon dioxide gas flowand the sequential loading, processing, and unloading of the feed andproduct solids can be envisioned as counter current flow of the solidsmovement from feed to product with respect to the flow of thesupercritical carbon dioxide. The directional loading, processing, andunloading is opposite to the flow of the supercritical carbon dioxide.This type of “continuous”, counter current operation is generallyreferred to as continuous, counter current, sequencing-batch operation.Therefore, when there are one or two batch stages, in series orparallel, the term “batch” tends to be used, and when there are three ormore stages, if they operate in parallel flow to the supercriticalcarbon dioxide, the term “batch” is also used. However, when theyoperate in counter current flow of the solids to the supercriticalcarbon dioxide, we call them counter current “sequencing-batch”simulating counter current flows of solid feed and solid product to theflow direction of the supercritical carbon dioxide. It should beunderstood that “continuous” can also define a process in which the feedand solvent are fed continuously through a fixed system and the productsare continuously removed.

For the conditions of Table 1, in order to achieve high contaminantremovals of approximately 98%, fairly low residence times ofapproximately 50 minutes (as noted in Run 6 in Table 1) should be used.In at least one possible embodiment, the process can produce high oilremoval levels, as well as produce an economical result. To obtain aneconomical result, a substantial amount of feed should be treated in aminimal time with a minimal amount of supercritical carbon dioxide(treat ratio).

It was found in this study that it was possible to operate at pressuresup to 10,000 PSI and temperatures up to 80-100° C., to load, process,and unload vessels (requiring filling, pressurization, warm-up,processing, and depressurization, cool-down, and unloading) in cycletimes less than 120 minutes, typically, 30 to 60 minutes; and, within 30to 60 minutes, there was enough time to carry out the labor-relatedloading and unloading of approximately 200 pounds of product solids. Thelabor related issues may or may not involve mechanical assistance, suchas robotics, if desired. Therefore, with a solids density ofapproximately 100 pounds per cubic foot, at least one possible reactorsize would be approximately 2 cubic feet based on extracted solids.Since the feed, according to at least one possible embodiment, can be upto 50% (by weight) contaminated oil, with the added weight of theoil-laden feed solids, the extractor volume could be 2.5 cubic feet. Itshould also be noted that, according to at least one possibleembodiment, the vessel is never or rarely totally full of feed, that is,there should be free-space in the vessels above/below the solids forequipment design and processing reasons.

In view of the above, extractor vessels may have substantial L/D's whenthe total volume per vessel is approximately 2.5 ft³. For example, an8-inch inner diameter vessel would be approximately 7 feet long. Forthis L/D, good mass transfer characteristics can be obtained for theextraction and desorption part of the cycle with nominal bed pressuredrops and treat ratios, and when processing in the supercritical region,temperature and pressure control are often or sometimes critical tomaintain purities.

For treat ratios of 5 to 30 gms CO₂/gm feed, for example, it can becalculated that sufficient mass transfer will exist in the 8-inch innerdiameter vessels containing beds of solids at slightly lower volumes.That is, in at least one possible embodiment, it may be practiced toload the vessels with feed by using “baskets”, which may be porous inconstruction, by lowering such baskets of feed into the vessel,extracting, and then raising and removing such baskets of products fromthe vessel. Since the baskets may contain feed up to 300 pounds, thebaskets, in at least one possible embodiment, can be of metal or steelconstruction, or other material construction, sufficient to withstandthe weight load over many repetitive loading and unloading cycles. Atleast a part, if not most all, of the basket should be porous to thesupercritical carbon dioxide for successful extraction and possiblydesorption of the contaminant oil from the bed of solids.

The number of processing vessels (stages) and the sequence of operation,co-current or counter current to the flow of supercritical carbondioxide, should be selected for efficiency and economic reasons. Forefficiency and economic reasons, counter current operations are usuallyor often more efficient and economical for large tonnage than co-currentor batch operations for the specific separation defined and describedherein. That is, the direction of filling and emptying the vessels iscounter current to the flow of supercritical carbon dioxide. On thisbasis, the number of vessels (stages) sufficient for a prescribed treatrate is directly a function of the production rate for the entire plant.For example, if a given 8-inch by 7-foot vessel will hold approximately300 pounds of feed and if N is the number of vessels, then 300N pound offeed can be processed at, say, a residence time of 60 minutes.Therefore, according to at least one possible embodiment, the productionrate (based on the feed) can be calculated as follows: For N=4, theplant can process 1200 pounds per hour, or approximately 14.4 tons perday (T/D) of feed; and for N=3, the plant can process approximately 10.8T/D. If the required residence time is 120 minutes, a similarcalculation would show that for 3 stages, the production rate would be5.4 T/D, and for 4 stages, the production rate would be 7.2 T/D (basedon feed flow).

One feature or aspect of an embodiment is believed at the time of thefiling of this patent application to possibly reside broadly in a methodof removing oil from a mixture of granular material and oil, comprisinghigh speed steel swarf, said method comprising the steps of: loadingsaid mixture of granular material and oil into an extraction vessel;contacting said mixture with supercritical carbon dioxide at a pressuregreater than 4300 PSI and at a temperature sufficient to remove asubstantial portion of said oil from said mixture of granular materialand oil; flowing a sufficient quantity of supercritical carbon dioxidethrough said mixture for a sufficient period of time to yield a reducedoil content solids product and supercritical carbon dioxide containingoil from said mixture of granular material and oil; separating saidsolids product from the supercritical carbon dioxide containing oil fromsaid solids product; and removing said solids product from theextraction vessel.

The components disclosed in the various publications, disclosed orincorporated by reference herein, may possibly be used in possibleembodiments of the present invention, as well as equivalents thereof.

Another feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in amethod of removing oil from a mixture of granular material and oil,comprising high speed steel swarf, said method comprising the steps of:loading said mixture of granular material and oil into an extractionvessel; contacting said mixture with supercritical carbon dioxide at apressure and at a temperature sufficient to remove a substantial portionof said oil from said mixture of granular material and oil; flowing asufficient quantity of supercritical carbon dioxide through said mixturefor a sufficient period of time to yield a reduced oil content solidsproduct and supercritical carbon dioxide containing oil from saidmixture of granular material and oil; separating said solids productfrom the supercritical carbon dioxide containing oil from said solidsproduct; and removing said solids product from the extraction vessel.

The purpose of the statements about the technical field is generally toenable the Patent and Trademark Office and the public to determinequickly, from a cursory inspection, the nature of this patentapplication. The description of the technical field is believed, at thetime of the filing of this patent application, to adequately describethe technical field of this patent application. However, the descriptionof the technical field may not be completely applicable to the claims asoriginally filed in this patent application, as amended duringprosecution of this patent application, and as ultimately allowed in anypatent issuing from this patent application. Therefore, any statementsmade relating to the technical field are not intended to limit theclaims in any manner and should not be interpreted as limiting theclaims in any manner.

Yet another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly in amethod of removing oil from swarf, said method comprising the steps of:loading said swarf into an extraction vessel; contacting said swarf withsupercritical carbon dioxide at a pressure greater than 4300 PSI and ata temperature sufficient to remove a substantial portion of said oilfrom said swarf; flowing a sufficient quantity of supercritical carbondioxide through said swarf for a sufficient period of time to yield areduced oil content solids product and supercritical carbon dioxidecontaining oil from said swarf; separating said solids product from thesupercritical carbon dioxide containing oil from said solids product;and removing said solids product from the extraction vessel.

U.S. provisional patent application 60/942,883, filed on Jun. 8, 2007,having inventors Robert J. BELTZ, Eugene J. GRESKOVICH, and RodgerMARENTIS, and title “METHOD FOR DEEP EXTRACTION OF CONTAMINANTS FROMGRINDING SWARFS AND SIMILAR MATERIALS USING SUPERCRITICAL CARBONDIOXIDE” is hereby incorporated by reference as if set forth in itsentirety herein.

Still another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly in amethod of removing oil from swarf, said method comprising the steps of:loading said swarf into an extraction vessel; contacting said swarf withsupercritical carbon dioxide at a pressure and at a temperaturesufficient to remove a substantial portion of said oil from said swarf;flowing a sufficient quantity of supercritical carbon dioxide throughsaid swarf for a sufficient period of time to yield a reduced oilcontent solids product and supercritical carbon dioxide containing oilfrom said swarf; separating said solids product from the supercriticalcarbon dioxide containing oil from said solids product; and removingsaid solids product from the extraction vessel.

The appended drawings in their entirety, including all dimensions,proportions and/or shapes in at least one embodiment of the invention,are accurate and are hereby included by reference into thisspecification.

A further feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in amethod for separating and recycling metals and contaminant fluids fromswarf comprising the steps of: a. providing a fixed bed or beds ofcontaminated feed particles in which the contaminant fluid is at anysaturation level; b. contacting said contaminated bed with supercriticalcarbon dioxide (SCCO₂) following at treat rates of less than 30 gmCO₂/gm of contaminated solids; c. providing the supercritical carbondioxide at pressures greater than 4300 PSI; d. providing sufficientcontacting time and solvent to feed ratio to yield a solids product witha contaminant level less than 3.26% by weight (greater than 85% oilremoval), such contacting time encompassing 120 minutes or less; e.separating the extracted contaminant by lowering the pressure (Flash) ofthe Supercritical carbon dioxide-contaminant extract to remove saidcontaminant by-product from the extract by flashing the carbon dioxideand leaving the contaminant liquid; f. selecting the pressure andtemperature in the Flash to minimize oil content in the recycled carbondioxide; g. removing the extracted solids product from the extractionvessel at or near ambient conditions; h. refilling the extraction vesseland repeating steps a) through g) as timely as desired.

U.S. provisional patent application 60/942,748, filed on Jun. 8, 2007,having inventors Robert J. BELTZ, Eugene J. GRESKOVICH, and RodgerMARENTIS, and title “DEEP EXTRACTION OF GRINDING SWARFS AND SIMILARMATERIALS USING SUPERCRITICAL CARBON DIOXIDE” is hereby incorporated byreference as if set forth in its entirety herein.

Another feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in themethod including at least one of (A), (B), (C), (D), (E), (F), (G), (H),(I), (J), (K), (L), (M), (N), (O), and (P), wherein (A), (B), (C), (D),(E), (F), (G), (H), (I), (J), (K), (L), (M), (N), (O), and (P) comprisethe following: (A) said metal waste by-product is from tool steelswarfs; (B) said granular waste by-product is high speed steel (HSS)grinding swarf; (C) said granular waste by-product is tungsten carbideswarf; (D) the contaminant liquid is either oil-based and/oraqueous-based; (E) the supercritical carbon dioxide is maintained at apressure level of at least 5000 PSI and a temperature of at least 60°C., to achieve greater than 88% oil removal; (F) the supercriticalcarbon dioxide is maintained at a pressure of at least 8700 PSI and atemperature of at least 80° C., but at a pressure less than 9200 PSI andtemperature less than 110° C., to achieve greater than 98.4% oilremoval; (G) the contaminant oil level in the extracted swarf product isless than 1.52% by weight; (H) the contaminant oil level in theextracted swarf product is less than 0.44% by weight; (I) less than3.26% by weight contaminant is desired on the solid product; (J) lessthan 1.52% by weight contaminant is desired on the solid product; (K)less than 0.44% by weight contaminant is desired on the solid product;(L) including a cycle of pressures and temperatures where at or nearequilibrium conditions are practiced in a process for containment fluidremoval with supercritical carbon dioxide; (M) the contaminant fluid isa hydrocarbon or mixtures of hydrocarbons; (N) the contaminated fluid isan aqueous contaminant; and (O) the contaminant fluid is a mixture ofhydrocarbons and aqueous-based components; and (P) the feed solids areany solid materials with similar particle-size ranges, yielding bedswith similar porosities and mass-transfer characteristics duringprocessing with supercritical carbon dioxide, such as tool steels andhigh speed steel.

The background information is believed, at the time of the filing ofthis patent application, to adequately provide background informationfor this patent application. However, the background information may notbe completely applicable to the claims as originally filed in thispatent application, as amended during prosecution of this patentapplication, and as ultimately allowed in any patent issuing from thispatent application. Therefore, any statements made relating to thebackground information are not intended to limit the claims in anymanner and should not be interpreted as limiting the claims in anymanner.

Yet another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly in amethod for treating, separating and recycling metallic solids andcontaminant fluids from high speed steel (HSS) grinding swarf such thatthe product metals contain less than 2.4% (by weight) contaminant fluidcomprising the steps of: a) providing a fixed bed (stage) of feed swarfthrough which supercritical carbon dioxide is passed, either up flow ordown; b) maintaining a plurality of stages through which thesupercritical carbon dioxide is passed counter current to the sequentialoperation of the stages; c) filling and emptying the stages of feedswarf and product swarf in a direction reverse of the flow ofsupercritical carbon dioxide; d) providing flowing supercritical carbondioxide at treat ratio between 10 and 30 gms CO₂/gm feed; e) maintainingthe stages at pressures greater than 4300 PSI; f) maintaining the stagesat temperatures greater than 60° C.; g) removing, on a continuous basis,and separating the contaminant fluids in the supercritical carbondioxide extract by one or more stages of pressure reduction; h)recompressing and reheating the flashed and purified carbon dioxide tothe original supercritical conditions and recycling back to the stages;i) removing the separated contaminant fluid from the process; j)removing the solids product, concurrent with step g), on asemi-continuous basis for each stage, replicating a counter currentmovement with respect to the flowing supercritical carbon dioxide; k)removing the solids product when the oil content is less than 2.4% byweight; l) emptying, recharging, and processing each stage as describedin step g) with a total cycle time less than 120 minutes for the wholeprocess; m) maintaining N stages within the Process, predicated by thedesired production rate; n) providing up to 120 minutes of residencetime in the extractor to permit 98+% oil removal; o) providing up to 120minutes of residence time for feed rates of 1 to 15 tons per day.

U.S. provisional patent application 60/942,759, filed on Jun. 8, 2007,having inventors Rodger MARENTIS, Robert J. BELTZ, and Eugene J.GRESKOVICH, and title “METHOD FOR NEARLY COMPLETE EXTRACTION OF GRINDINGSWARFS AND SIMILAR MATERIALS USING SUPERCRITICAL CARBON DIOXIDE” ishereby incorporated by reference as if set forth in its entirety herein.

Still another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly inthe method including at least one of (A), (B), (C), (D), (E), and (F),wherein (A), (B), (C), (D), (E), and (F) comprise the following: (A)said high speed steel (HSS) swarf is treated such that the productmetals contain a contaminant fluid content of less than 1.5% (byweight); (B) the product metals contain a contaminant fluid content ofless than 0.44% (by weight); (C) the contaminant fluid in high speedsteel (HSS) grinding swarf is primarily an oil-based contaminant; (D)the contaminant fluid in high speed steel (HSS) grinding swarf isprimarily an aqueous-based contaminant; (E) the contaminant fluid inhigh speed steel (HSS) grinding swarf is a co-mixture of aqueous andoil-based compounds; and (F) including conditions that result in ametallic product that contains as little as no (0%) contaminant,comprising the steps of: a) providing residence times in the extractorhigher than 120 minutes; b) providing flowing supercritical carbondioxide at treat ratios higher than 30 gms CO₂/gm feed; c) maintainingas few stages as possible, down to one stage, predicated on theproduction rate desired; d) optimizing steps a) through c) such that apreferred set of conditions yields a contaminant level as low aspossible.

All, or substantially all, of the components and methods of the variousembodiments may be used with at least one embodiment or all of theembodiments, if more than one embodiment is described herein.

A further feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in amethod for separating and recycling metals and contaminant fluids fromswarf comprising the steps of: a) providing a fixed bed or beds ofcontaminated feed particles in which the contaminant is at anysaturation level; b) contacting said contaminated bed with supercriticalcarbon dioxide (SCCO₂) flowing at treat rates of less than 30 gms CO₂/gmsample; c) providing the supercritical carbon dioxide at temperaturesgreater than 60° C., and; d) providing the supercritical carbon dioxideat pressures greater than 4300 PSI; e) providing sufficient contactingtime and solvent to feed ratio to yield a solids product with acontaminant level less than 2.4% by weight or other desired contentlevel; f) separating the extracted oil by lowering the pressure of thesupercritical carbon dioxide oil extract to remove said oil by-productfrom the extract; g) removing the extracted solids product from theextraction vessel at or near ambient conditions; h) refilling theextraction vessel and repeating steps a) through f) as timely asdesired.

The purpose of the statements about the object or objects is generallyto enable the Patent and Trademark Office and the public to determinequickly, from a cursory inspection, the nature of this patentapplication. The description of the object or objects is believed, atthe time of the filing of this patent application, to adequatelydescribe the object or objects of this patent application. However, thedescription of the object or objects may not be completely applicable tothe claims as originally filed in this patent application, as amendedduring prosecution of this patent application, and as ultimately allowedin any patent issuing from this patent application. Therefore, anystatements made relating to the object or objects are not intended tolimit the claims in any manner and should not be interpreted as limitingthe claims in any manner.

Another feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in themethod, including at least one of (A), (B), (C), (D), (E), (F), (G),(H), and (I), wherein (A), (B), (C), (D), (E), (F), (G), (H), and (I)comprise the following: (A) said granular metal waste by-product is highspeed steel (HSS) swarf; (B) the contaminant liquid is oil-based and/oraqueous-based; (C) the supercritical carbon dioxide is maintained at apressure level of at least 5000 PSI and a temperature of at least 68°C.; (D) the supercritical carbon dioxide is maintained at a pressure ofat least 8700 PSI and a temperature of at least 80° C., but at apressure less than 9200 PSI and temperature less than 110° C.; (E) thecontaminant oil level in the extracted swarf product is less than 1.5%by weight; (F) the contaminant oil level in the extracted swarf productis less than 0.45% by weight; (G) less than 2.4% by weight contaminantis desired on the solid product; (H) less than 1.5% by weightcontaminant is desired on the solid product; and (I) less than 0.45% byweight contaminant is desired on the solid product.

All of the patents, patent applications and publications recited herein,and in the Declaration attached hereto, are hereby incorporated byreference as if set forth in their entirety herein.

Yet another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly in amethod for separating and recycling metals and contaminant fluid fromswarf comprising the steps of: a. Providing a fixed bed of contaminatedparticles in which the contaminant feed particles are placed; b.Contacting said bed of contaminated particles with supercritical carbondioxide; c. Providing the supercritical carbon dioxide at temperaturesgreater than 60° C. and less than 150° C.; d. Providing thesupercritical carbon dioxide at pressures greater than 5000 PSI and lessthan 9200 PSI; e. Providing sufficient contacting time and solvent tofeed ratio to yield a solids product with a contaminant level less than2.4 percent by weight; f. Separating the extracted oil by lowering thepressure of the supercritical carbon dioxide oil extract to remove saidoil by product from the extract; g. Removing the extracted solidsproduct from the extraction vessel at or near ambient conditions; h.Refilling the extraction vessel and repeating steps a through f astimely as desired.

The summary is believed, at the time of the filing of this patentapplication, to adequately summarize this patent application. However,portions or all of the information contained in the summary may not becompletely applicable to the claims as originally filed in this patentapplication, as amended during prosecution of this patent application,and as ultimately allowed in any patent issuing from this patentapplication. Therefore, any statements made relating to the summary arenot intended to limit the claims in any manner and should not beinterpreted as limiting the claims in any manner.

Still another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly inthe method including at least one of (A), (B), (C), (D), (E), and (F),wherein (A), (B), (C), (D), (E), and (F) comprise the following: (A)said swarf comprises high speed steel HSS swarf; (B) the contaminantliquid is oil based and/or aqueous based; (C) the supercritical carbondioxide is maintained at a pressure level of at least 5000 PSI and atemperature of at least 68° C.; (D) the supercritical carbon dioxide ismaintained at a pressure level of at least 5000 PSI and a temperature ofat least 68° C.; (E) the supercritical carbon dioxide is maintained at apressure level of at least 5000 PSI and a temperature of at least 68°C.; and wherein the contaminant oil level in the extracted swarf productis less than 1.5 percent by weight; and (H) the supercritical carbondioxide is maintained at a pressure of at least 8700 PSI and atemperature of at least 80° C.; and wherein the contaminant oil level inthe extracted swarf product is less than 0.45 percent by weight.

It will be understood that any or all examples of patents, publishedpatent applications, and other documents which are included in thisapplication and including those which are referred to in paragraphswhich state “Some examples of . . . which may possibly be used in atleast one possible embodiment of the present application . . . ” maypossibly not be used or useable in any one or more or any embodiments ofthe application.

The sentence immediately above relates to patents, published patentapplications and other documents either incorporated by reference or notincorporated by reference.

A further feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in amethod for treating and separating contaminant fluids, either oil and/oraqueous, from swarf for reuse or other industrial purposes by: (A) amethod for separating and recycling metals and contaminant fluid fromswarf comprising the steps of: a. Providing a fixed bed of contaminatedparticles in which the contaminant particles are placed; b. Contactingsaid bed of contaminated particles with supercritical carbon dioxide; c.Providing the supercritical carbon dioxide at temperatures greater than60° C. and less than 150° C.; d. Providing the supercritical carbondioxide at pressures greater than 5000 PSI and less than 9200 PSI; e.Providing sufficient contacting time and solvent to feed ratio to yielda solids product with a contaminant level less than 2.4 percent byweight; f. Separating the extracted oil by lowering the pressure of thesupercritical carbon dioxide oil extract to remove said oil by productfrom the extract; g. Removing the extracted solids product from theextraction vessel at or near ambient conditions; h. Refilling theextraction vessel and repeating steps a through f as timely as desired,and wherein less than 2.4 percent by weight, contaminant is desired onthe solid product.

All of the references and documents, cited in any of the documents citedherein, are hereby incorporated by reference as if set forth in theirentirety herein. All of the documents cited herein, referred to in theimmediately preceding sentence, include all of the patents, patentapplications and publications cited anywhere in the present application.

Another feature or aspect of an embodiment is believed at the time ofthe filing of this patent application to possibly reside broadly in themethod, wherein the supercritical carbon dioxide is maintained at apressure level of at least 5000 PSI and a temperature of at least 68°C., and wherein less than 1.5 percent by weight contaminant is desiredon the solid product.

The description of the embodiment or embodiments is believed, at thetime of the filing of this patent application, to adequately describethe embodiment or embodiments of this patent application. However,portions of the description of the embodiment or embodiments may not becompletely applicable to the claims as originally filed in this patentapplication, as amended during prosecution of this patent application,and as ultimately allowed in any patent issuing from this patentapplication. Therefore, any statements made relating to the embodimentor embodiments are not intended to limit the claims in any manner andshould not be interpreted as limiting the claims in any manner.

Yet another feature or aspect of an embodiment is believed at the timeof the filing of this patent application to possibly reside broadly inthe method, wherein the supercritical carbon dioxide is maintained at apressure level of at least 5000 PSI and a temperature of at least 68°C., and wherein less than 0.45 percent by weight contaminant is desiredon the solid product.

The details in the patents, patent applications and publications may beconsidered to be incorporable, at applicant's option, into the claimsduring prosecution as further limitations in the claims to patentablydistinguish any amended claims from any applied prior art.

The purpose of the title of this patent application is generally toenable the Patent and Trademark Office and the public to determinequickly, from a cursory inspection, the nature of this patentapplication. The title is believed, at the time of the filing of thispatent application, to adequately reflect the general nature of thispatent application. However, the title may not be completely applicableto the technical field, the object or objects, the summary, thedescription of the embodiment or embodiments, and the claims asoriginally filed in this patent application, as amended duringprosecution of this patent application, and as ultimately allowed in anypatent issuing from this patent application. Therefore, the title is notintended to limit the claims in any manner and should not be interpretedas limiting the claims in any manner.

The abstract of the disclosure is submitted herewith as required by 37C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b):

-   -   A brief abstract of the technical disclosure in the        specification must commence on a separate sheet, preferably        following the claims, under the heading “Abstract of the        Disclosure.” The purpose of the abstract is to enable the Patent        and Trademark Office and the public generally to determine        quickly from a cursory inspection the nature and gist of the        technical disclosure. The abstract shall not be used for        interpreting the scope of the claims.        Therefore, any statements made relating to the abstract are not        intended to limit the claims in any manner and should not be        interpreted as limiting the claims in any manner.

The embodiments of the invention described herein above in the contextof the preferred embodiments are not to be taken as limiting theembodiments of the invention to all of the provided details thereof,since modifications and variations thereof may be made without departingfrom the spirit and scope of the embodiments of the invention.

1. An industrial method of removing cutting oil from tool steel swarf inan extraction vessel, said method comprising the steps of: (a) openingsaid extraction vessel and loading said tool steel swarf into saidextraction vessel; (b) closing said extraction vessel to seal said toolsteel swarf therein; (c) removing a substantial portion of said cuttingoil from said tool steel swarf by flowing a sufficient quantity ofsupercritical carbon dioxide through said tool steel swarf for a periodof time sufficient to remove a substantial portion of said cutting oilfrom said tool steel swarf, and at a temperature sufficient to remove asubstantial portion of said cutting oil from said tool steel swarf, andat a pressure of about 8700 PSI and at a temperature of about eightydegrees Celsius or greater; (d) separating said tool steel swarf fromsaid supercritical carbon dioxide containing cutting oil; and (e)opening said extraction vessel and removing said tool steel swarf fromsaid extraction vessel.
 2. The method according to claim 1, wherein saidstep (c) comprises removing a substantial portion of said cutting oilfrom said tool steel swarf essentially solely by flowing a sufficientquantity of supercritical carbon dioxide through said tool steel swarf.3. The method according to claim 2, wherein said extraction vessel hasimmovable side and end walls during a step of removal of cutting oilfrom tool steel swarf, and wherein said step (b) comprises closing saidextraction vessel to provide immovable side and end walls during removalof cutting oil from tool steel swarf.
 4. The method according to claim3, wherein said method comprises treating 1 to 15 tons of swarf per day.5. The method according to claim 4, wherein said method comprises oneof: using an extraction vessel having an interior volume of 2-2.5 cubicfeet; and using an extraction vessel having an inner diameter of about 8inches and a length of about 7 feet.
 6. The method according to claim 4,wherein: said step of loading swarf into said extraction vesselcomprises inserting porous baskets containing 100-300 pounds of swarfinto said extraction vessel and flowing supercritical carbon dioxidethrough said baskets; and said step of removing swarf from saidextraction vessel comprises removing said baskets full of swarf.
 7. Themethod according to claim 4, wherein: said step (b) comprises contactingsaid swarf with said supercritical carbon dioxide at a temperature inthe range of at least 80° C. to at most 110° C.; said step (c) comprisesflowing said supercritical carbon dioxide through said swarf for 120minutes or less at a treat ratio of between 5 and 30 grams of carbondioxide per gram of high speed steel swarf; and said step (e) comprisesremoving said high speed steel swarf from said extraction vessel at ornear ambient conditions, said method further comprises the steps of: (f)lowering the pressure and temperature of cutting oil-laden supercriticalcarbon dioxide to separate said cutting oil from said cutting oil-ladensupercritical carbon dioxide; and (g) recycling said supercriticalcarbon dioxide for reuse in the removal of cutting oil from swarf,either with the addition of fresh, make-up, carbon dioxide at any ratio,or without the addition of fresh, make-up, carbon dioxide at any ratio;said method further comprises removing an aqueous liquid or a mixture ofaqueous and oil liquids with said cutting oil from said tool steelswarf; said step (f) comprises selecting a predetermined lower pressureand temperature sufficient to minimize cutting oil content in thesupercritical carbon dioxide to be recycled; said step (c) comprisesflowing supercritical carbon dioxide one of: in the same direction as,transverse to, or counter to the flow of swarf, which flow of swarf isone of: a horizontal flow, a vertically upward flow, or a verticallydownward flow; said step (g) comprises recompressing and reheating thecarbon dioxide to the original supercritical conditions; said steps(a)-(g) are performed in a plurality of separate extraction vesselsoperating in parallel, sequentially, or in a cascade, eithercontinuously or semi-continuously, with a cycle time of less than 120minutes for each extraction vessel, and a total cycle time of less than120 minutes times the number of extraction vessels for the wholeprocess.
 8. The method according to claim 1, wherein said step (c)comprises removing greater than 98% of said cutting oil and reducing thecutting oil level in said swarf to less than 0.44% by weight.
 9. Anindustrial method of removing cutting oil from tool steel swarf in anextraction vessel, said method comprising the steps of: (a) opening saidextraction vessel and loading said tool steel swarf into said extractionvessel; (b) closing said extraction vessel to seal said tool steel swarftherein; (c) removing a substantial portion of said cutting oil fromsaid tool steel swarf essentially solely by flowing a sufficientquantity of supercritical carbon dioxide through said tool steel swarffor a period of time sufficient to remove a substantial portion of saidcutting oil from said tool steel swarf, and at a pressure of about 8700PSI and at a temperature of about eighty degrees Celsius or greatersufficient to remove a substantial portion of said cutting oil from saidtool steel swarf; (d) separating said tool steel swarf from saidsupercritical carbon dioxide containing cutting oil; and (e) openingsaid extraction vessel and removing said tool steel swarf from saidextraction vessel.
 10. The method according to claim 9, wherein saidextraction vessel has immovable side and end walls during a step ofremoval of cutting oil from tool steel swarf, and wherein said step (b)comprises closing said extraction vessel to provide immovable side andend walls during removal of cutting oil from tool steel swarf.
 11. Themethod according to claim 10, wherein said method comprises treating atleast one ton of swarf per day.
 12. The method according to claim 11,wherein said method comprises one of: using an extraction vessel havingan interior volume of 2-2.5 cubic feet; and using an extraction vesselhaving an inner diameter of about 8 inches and a length of about 7 feet.13. The method according to claim 11, wherein: said step of loadingswarf into said extraction vessel comprises inserting porous baskets ofswarf into said extraction vessel and flowing supercritical carbondioxide through said baskets; and said step of removing swarf from saidextraction vessel comprises removing said baskets full of swarf.
 14. Themethod according to claim 11, wherein: said method further comprisesremoving cutting oil from high speed steel swarf; said step (c)comprises contacting said high speed steel swarf with said supercriticalcarbon dioxide; said step (c) comprises flowing said supercriticalcarbon dioxide through said high speed steel swarf for 120 minutes orless at a treat ratio of between 5 and 30 grams of carbon dioxide pergram of high speed steel swarf; said step (e) comprises removing saidhigh speed steel swarf from said extraction vessel at or near ambientconditions; said method further comprises the steps of: (f) lowering thepressure and temperature of cutting oil-laden supercritical carbondioxide to separate said cutting oil from said cutting oil-ladensupercritical carbon dioxide; and (g) recycling said supercriticalcarbon dioxide for reuse in the removal of cutting oil from high speedsteel swarf, either with the addition of fresh, make-up, carbon dioxideat any ratio, or without the addition of fresh, make-up, carbon dioxideat any ratio; said method further comprises removing an aqueous liquidor a mixture of aqueous and oil liquids with said cutting oil from saidhigh speed steel swarf; said step (f) comprises selecting apredetermined lower pressure and temperature sufficient to minimizecutting oil content in the supercritical carbon dioxide to be recycled;said step (c) comprises flowing supercritical carbon dioxide one of: inthe same direction as, transverse to, or counter to the flow of highspeed steel swarf, which flow of high speed steel swarf is one of: ahorizontal flow, a vertically upward flow, or a vertically downwardflow; said step (c) comprises flowing said supercritical carbon dioxidethrough said high speed steel swarf at a treat ratio of between 10 and30 grams of carbon dioxide per gram of high speed steel swarf; said step(g) comprises recompressing and reheating the carbon dioxide to theoriginal supercritical conditions; said steps (a)-(g) are performed in aplurality of separate extraction vessels operating in parallel,sequentially, or in a cascade, either continuously or semi-continuously,with a cycle time of less than 120 minutes for each extraction vessel,and a total cycle time of less than 120 minutes times the number ofextraction vessels for the whole process; and said method furthercomprises providing up to 120 minutes of residence time per vessel forfeed rates of 1 to 15 tons per day.
 15. An industrial method of removingcutting oil from tool steel swarf in an extraction vessel havingimmovable side and end walls during a step of removal of cutting oilfrom tool steel swarf, said method comprising the steps of: (a) openingsaid extraction vessel and loading at least 100 pounds of said toolsteel swarf into said extraction vessel; (b) closing said extractionvessel to provide immovable side and end walls during a step of removalof cutting oil from tool steel swarf and to seal said tool steel swarftherein; (c) removing a substantial portion of said cutting oil fromsaid tool steel swarf by flowing a sufficient quantity of supercriticalcarbon dioxide through said tool steel swarf for a period of timesufficient to remove a substantial portion of said cutting oil from saidtool steel swarf, and at a pressure of about 8700 PSI and at atemperature of about eighty degrees Celsius or greater sufficient toremove a substantial portion of said cutting oil from said tool steelswarf; (d) separating said tool steel swarf from said supercriticalcarbon dioxide containing cutting oil; and (e) opening said extractionvessel and removing said tool steel swarf from said extraction vessel.16. The method according to claim 15, wherein said method comprises:removing cutting oil from high speed steel swarf; and treating 1 to 15tons of swarf per day.
 17. The method according to claim 16, whereinsaid method comprises using an extraction vessel having an innerdiameter of about 8 inches and a length of about 7 feet.
 18. The methodaccording to claim 16, wherein said method comprises using an extractionvessel having an interior volume of 2-2.5 cubic feet.
 19. The methodaccording to claim 16, wherein: said step of loading swarf into saidextraction vessel comprises inserting porous baskets of swarf into saidextraction vessel and flowing supercritical carbon dioxide through saidbaskets; and said step of removing swarf from said extraction vesselcomprises removing said baskets full of swarf.
 20. The method accordingto claim 16, wherein said step (c) comprises removing greater than 88%of said cutting oil and reducing the cutting oil level in said swarf toless than 3.26% by weight.